Form 8-K

8-K — Replimune Group, Inc.

Accession: 0001104659-26-042141

Filed: 2026-04-13

Period: 2026-04-10

CIK: 0001737953

SIC: 2836 (BIOLOGICAL PRODUCTS (NO DIAGNOSTIC SUBSTANCES))

Item: Regulation FD Disclosure

Item: Other Events

Item: Financial Statements and Exhibits

Documents

8-K — tm2611633d1_8k.htm (Primary)

EX-99.1 — EXHIBIT 99.1 (tm2611633d1_ex99-1.htm)

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UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

Washington, D.C. 20549

FORM 8-K

CURRENT REPORT

Pursuant to Section 13 or 15(d)

of the Securities Exchange Act of 1934

Date of Report (Date of earliest event

reported): April 10, 2026

REPLIMUNE GROUP, INC.

(Exact name of registrant as specified in its charter)

Delaware

001-38596

82-2082553

(State or other jurisdiction

of incorporation)

(Commission

File Number)

(IRS Employer

Identification Number)

500

Unicorn Park Drive

Suite 303

Woburn, MA 01801

(Address of principal executive offices, including Zip Code)

Registrant’s telephone number, including

area code: (781) 222-9600

Check the appropriate box below if the Form 8-K filing is

intended to simultaneously satisfy the filing obligation of the registrant under any of the following provisions:

¨ Written communications pursuant to Rule 425 under the Securities Act (17 CFR

230.425)

¨ Soliciting material pursuant to Rule 14a-12 under the Exchange Act (17 CFR

240.14a-12)

¨ Pre-commencement communications pursuant to Rule 14d-2(b) under the Exchange Act (17 CFR

240.14d-2(b))

¨ Pre-commencement communications pursuant to Rule 13e-4(c) under the Exchange Act (17 CFR

240.13e-4(c))

Securities registered pursuant to Section 12(b) of the Act:

Title of each class

Trading

Symbol(s)

Name of each exchange on which registered

Common Stock, par value $0.001 per share

REPL

The Nasdaq Stock Market LLC

(Nasdaq Global Select Market)

Indicate

by check mark whether the registrant is an emerging growth company as defined in Rule 405 of the Securities Act of 1933

(§230.405 of this chapter) or Rule 12b-2 of the Securities Exchange Act of 1934 (§240.12b-2 of this

chapter). Emerging growth company ¨

If an

emerging growth company, indicate by check mark if the registrant has elected not to use the extended transition period for

complying with any new or revised financial accounting standards provided pursuant to Section 13(a) of the Exchange Act. ¨

Item 7.01 Regulation

FD Disclosure.

On April 10, 2026, Replimune

Group, Inc. (the “Company”) issued a news release announcing that the U.S. Food and Drug Administration (the “FDA”)

has issued a second Complete Response Letter regarding the Biologics License Application (“BLA”) for RP1 (vusolimogene oderparepvec)

in combination with nivolumab for the treatment of advanced melanoma. A copy of such news release is furnished as Exhibit 99.1 to this

Current Report on Form 8-K.

In accordance with General

Instruction B.2 of Form 8-K, the information in Item 7.01 of this Current Report on Form 8-K, including Exhibit 99.1, shall

not be deemed “filed” for the purposes of Section 18 of the Securities Exchange Act of 1934, as amended (the “Exchange

Act”), or otherwise subject to the liabilities of that section, nor shall it be deemed incorporated by reference in any filing under

the Securities Act of 1933, as amended, or the Exchange Act, except as expressly stated by specific reference in such filing.

Item 8.01 Other Events.

On April 10, 2026, the Company received a second

Complete Response Letter from the FDA regarding the Company’s BLA for RP1 (vusolimogene oderparepvec) in combination with nivolumab

for the treatment of advanced melanoma.

Item 9.01 Financial

Statements and Exhibits.

Exhibit No.

Description

99.1

News

Release dated April 10, 2026

104

Cover page interactive data file (formatted as Inline XBRL)

SIGNATURES

Pursuant to the requirements of the Securities Exchange Act of 1934, as amended, the registrant has duly caused this report to be signed

on its behalf by the undersigned hereunto duly authorized.

REPLIMUNE GROUP, INC.

Date: April 10, 2026

By:

/s/ Sushil Patel

Sushil Patel

Chief Executive Officer

EX-99.1 — EXHIBIT 99.1

EX-99.1

Filename: tm2611633d1_ex99-1.htm · Sequence: 2

Exhibit 99.1

Replimune Receives Complete Response Letter

from the FDA for RP1 Biologics License Application for the Treatment of Advanced Melanoma

WOBURN, Mass., April 10, 2026 (GLOBE NEWSWIRE) – Replimune

Group, Inc. (NASDAQ: REPL), a clinical stage biotechnology company pioneering the development of novel oncolytic immunotherapies,

today announced that the company received a complete response letter (CRL) from the U.S. Food and Drug Administration (FDA) for the

Company’s Biologics License Application (BLA) for RP1 in combination with nivolumab for the treatment of advanced

melanoma.

Replimune disagrees with the FDA about whether the data set, upon

which breakthrough therapy designation was awarded, is sufficient to allow this promising medicine to be made available to advanced cancer

patients. In the IGNYTE trial, patients with confirmed progression on an anti-PD-1 based regimen who received RP1 plus nivolumab had

a 34% response rate with a median duration of 24.8 months with a favorable safety profile.

“It is deeply disappointing that the FDA has not exercised regulatory

flexibility to meet patients’ needs given the data supporting strong efficacy and the favorable safety profile. Approximately 8,500

Americans with advanced melanoma die every year. The country's foremost melanoma specialists stood behind the RP1 data. Patients and

caregivers pleaded for urgency. All of it was met with inconsistent communication and a fragmented and slow-moving regulatory process

which clearly puts U.S. innovation at risk,” said Sushil Patel, Ph.D., CEO of Replimune. “As we previously communicated,

without timely accelerated approval, the development of RP1 will not be viable. We are devastated for our committed employees who have

worked tirelessly for patients but at this point we have no choice but to eliminate jobs, including substantially scaling back our U.S.

based manufacturing operations. A treatment desperately needed by patients will not be available. Not because the medicine failed. Because

the system did.”

Inconsistent agency process and communication thwarts innovation

With the CRL, the company learned that a different review team was

appointed for the resubmission and replaced the prior team who had interacted with the company. A senior member of the prior review team

stated publicly that the “BLA clinical team thought the applicant had provided adequate evidence to support contribution of effect

of RP1 plus nivolumab but leadership did not agree.” The new team did not meet with the company during the review process despite

the company offering.

In the CRL, the agency appears to have contradicted their positions

expressed at the September 2025 Type A meeting, including on the following points:

· After testimony from

melanoma experts, the agency did not raise further concerns about the heterogeneity of the

patient population in IGNYTE and acknowledged that randomizing patients to an anti-PD1 only

arm in the confirmatory study was not feasible.

· Following an agency

suggestion, the company submitted a proposal for a descriptive analysis from IGNYTE-3 supporting

contribution of components. The company also included data from IGNYTE showing median progression

free survival on RP1 plus nivolumab was 30.6 months compared to 4.4 months on their prior

PD-1 based regimen. The company requested feedback, however, the FDA did not respond and

subsequently accepted the resubmission as a complete response to the July 2025 CRL.

· The FDA raised several

points related to tumor assessment methodology. As requested by the FDA, responses in IGNYTE

were assessed using RECIST 1.1 without modifications. In addition, the company provided detailed

analyses showing no material difference in response rates between injected and non-injected

lesions. The company also provided a comprehensive analysis which showed that biopsies and

surgical interventions did not impact tumor response.

Prior to the original BLA submission, standard regulatory meetings

were conducted to discuss trial design, patient population, and the BLA package requirements. While a randomized controlled trial was

preferred, the FDA suggested in the March 2021 Type B minutes that if the data was sufficiently compelling, a single arm trial could

be acceptable for consideration under accelerated approval. At the subsequent pre-BLA meeting, the FDA stated “we do not object

to your proposal to submit a BLA based primarily on data from the cohort of patients (n=140) in the Phase 2 IGNYTE trial who had advanced

melanoma and progressed while being treated with prior anti-PD-1 based therapy.” The company subsequently submitted a BLA which

was accepted with breakthrough therapy designation and granted priority review. Based on feedback from the FDA, the company initiated

a resource-intensive global Phase 3 trial, IGNYTE-3, to satisfy the regulatory requirement that a confirmatory study be underway for

an accelerated approval.

About Melanoma

Melanoma is the fifth most common cancer, with approximately 112,000

new cases estimated in the U.S. in 2026, and the most lethal form of skin cancer, accounting for nearly 8,500 deaths annually. Standard

of care therapy includes treatment with immune checkpoint blockade, to which approximately half of patients will not respond or will

progress after treatment. Melanoma is considered advanced when the cancer spreads beyond the primary tumor to other parts of the body.

About RP1

RP1 (vusolimogene oderparepvec) is Replimune’s lead product

candidate and is based on a proprietary strain of herpes simplex virus engineered and genetically armed with a fusogenic protein (GALV-GP

R-) and GM-CSF intended to maximize tumor killing potency, the immunogenicity of tumor cell death, and the activation of a systemic anti-tumor

immune response.

About Replimune

Replimune Group, Inc., headquartered in Woburn, MA, was founded in

2015 with the mission to transform cancer treatment by pioneering the development of novel oncolytic immunotherapies. Replimune’s

proprietary RPx platform is based on a potent HSV-1 backbone intended to maximize immunogenic cell death and the induction of a systemic

anti-tumor immune response. The RPx platform is intended to ignite local activity consisting of direct selective virus-mediated killing

of the tumor resulting in the release of tumor derived antigens and altering of the tumor microenvironment to then activate a strong

and durable systemic response. The RPx product candidates are expected to be synergistic with most established and experimental cancer

treatment modalities, leading to the versatility to be developed alone or combined with a variety of other treatment options. For more

information, please visit www.replimune.com.

Forward Looking Statements

This press release contains forward looking statements within the

meaning of Section 27A of the Securities Act of 1933, as amended, and Section 21E of the Securities Exchange Act of 1934, as amended,

including statements regarding our interactions with the FDA and other statements identified by words such as “could,” “expects,”

“intends,” “hope,” “may,” “plans,” “potential,” “should,” “will,”

“would,” or similar expressions and the negatives of those terms. Forward-looking statements are not promises or guarantees

of future performance, and are subject to a variety of risks and uncertainties, many of which are beyond our control, and which could

cause actual results to differ materially from those contemplated in such forward-looking statements. These factors include risks related

to our limited operating history, our ability to generate positive clinical trial results for our product candidates, the costs and timing

of operating our in-house manufacturing facility, the timing and scope of regulatory approvals, if any, our ability to resolve the issues

identified in the CRL in a manner satisfactory to the FDA and to us and the timing thereof, the availability of combination therapies

needed to conduct our clinical trials, changes in laws and regulations to which we are subject, competitive pressures, our ability to

identify additional product candidates, political and global macro factors including the impact of a global pandemic and related public

health issues and the ongoing political and military conflicts, including trade conflicts, and other risks as may be detailed from time

to time in our Annual Reports on Form 10-K and Quarterly Reports on Form 10-Q and other reports we file with the Securities and Exchange

Commission. Our actual results could differ materially from the results described in or implied by such forward-looking statements. Forward-looking

statements speak only as of the date hereof, and, except as required by law, we undertake no obligation to update or revise these forward-looking

statements.

Investor Inquiries

Chris Brinzey

ICR Healthcare

339.970.2843

chris.brinzey@icrhealthcare.com

Media Inquiries

Arleen Goldenberg

Replimune

917.548.1582

media@replimune.com

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